The unfolding disaster at Japans nuclear power plants, in the wake of catastrophic earthquake and tsunamis, all too graphically demonstrates why California's San Onofre and Diablo Canyon nukes should be shut down immediately.

As a result of the 8.9 earthquake and subsequent tsunamis in Japan, the 40 year old Fukushima No. 1 nuclear reactor there is in big trouble.

Fukushima 1 is one of six reactors at the Daiichi nuclear complex 150 miles north of Tokyo.

The LA Times reported on March 11 that the nuclear reactor’s “emergency cooling system has not been functioning properly and authorities fear a meltdown.”

Japanese officials initially ordered 3000 people living within 2 miles of Fukushima 1 to evacuate. They also instructed others residing within six miles to stay in their homes.

Fifteen other nuclear plants, out of 33 in Japan, also shut down because of the 8.9 shaker.

Uncool Nuke

Inside a reactor a controlled nuclear reaction produces heat that is subsequently is used to generate electricity. But that reaction also creates lots of deadly radioactivity and “excess” heat.

If the nuclear fuel gets too hot, it will start to melt, causing potentially catastrophic amounts of radioactivity to threaten to escape into the environment.

To avoid this calamity, the nuclear fuel must be constantly bathed in cooling water. The system that supplies the cooling water is powered by electricity.

At Fukushima 1, the supply of cooling water was stopped when the earthquake knocked out the electrical supply that powered the cooling system. Ironically, the source of that electricity must come from outside the plant.

There is a backup system of diesel powered generators at Fukushima 1, but that system also failed when a tsunami hit the nuke, which is located on the ocean.

The final line of defense to prevent a meltdown consists of batteries that can power the cooling system. The Times reported that these batteries went into operation “less than an hour” after the disaster cut off the juice.

But these batteries only last about eight hours, a stretch of time that quickly passed at Fukushima 1.

The Washington Post reported that US nuclear safety expert Margaret Harding, who has been “in touch with experts in Japan,” said “the entire complex was blacked out for a period of time before new backup generators arrived.”

The US Air Force and Japanese ground troops had been racing replacement generators to the troubled site, the LA Times reported.

Saturday: Explosion, Meltdown, Mass Evacuations

Nevertheless, pressure inside the reactor containment building rose “to 50% above normal,” according to the Times. To deal with this dangerous development, authorities at the plant started venting radioactive gases to the outside environment.

As usual, they claimed this is a safe practice. And while it might be preferable to the pressure inside the containment building blowing it apart, the National Academy of Science has established that there is no such thing as a risk free dose of radiation.

On Saturday further evacuations were ordered, including people living around the nearby Daini nuclear complex, which has four reactors. Those ordered to evacuate numbered in total over 200,000. Reuters reported that radiation levels in the control room at the Fukushima 1 plant were “1000 times the normal level.”

”Only the gravest danger would justify an evacuation at such a moment,” former NRC commissioner Paul Bradford told the Washington Post.

Then the government announced that the cooling system at Fukushima 2 “can no longer cool radioactive substances,” CNN reported.

Subsequently an explosion at Fukushima 1 blew apart the building that housed the nuclear reactor fuel and its containment building. The Post reported that this was likely a sign that a meltdown was going on in the reactor.

“The explosion was caused by hydrogen,” the Post reported, “that could only have been produced from inside the reactor vessel by exposure of zirconium cladding [covering] that surrounds [nuclear] fuel rods. The rods are supposed to be covered by water, but at extremely high temperatures steam reacts with zirconium and produces hydrogen.”

Another indication that a meltdown was underway, according to the Post, was that Japan’s Nuclear Industrial Safety Agency reported the plant “could be nearing meltdown and that two radioactive substances, cesium and radioactive iodine, were detected nearby.”

The government also was distributing potassium iodide to people near the plant, which blocks radioactive iodine from entering the human thyroid, where it can cause cancer.

Levels of radiation at the Fukishima plant were well above the legal limit, Reuters reported on Sunday. Reuters also reported “Japanese news reports cooling water in the plant decreased so much that up to three metres of fuel rods were exposed."

Tokyo Electric, the owner of Fudushima 1, has been flooding its reactor core with sea water and boric acid to cool off the fuel rods. Even if this succeeds, it’s likely this dosage will further ruin the plant.

Toyko Electric is venting radiation into the environment from other Fukushima nuclear plants. Most of them seem to have compromised cooling systems as well.

Another of them is reported to be suffering a meltdown as well.

Another potential problem looms in the spent fuel pool at these nuclear complexes. These hold nuclear fuel rods that are commercially spent but are still highly radioactive. Like the fuel rods in the reactors, they have to be kept cool, or else they will melt down as well. These cooling systems are electrically operated as well.

The Post also reported “23 reactors in the US have the same design as Fukushima 1.”

Why It Can Happen Here

On Friday’s Pacifica radio show, “Letters and News,” guest Robert Alvarez of the Institute of Policy Studies, a former US Department of Energy official, reported that California’s two operating nuclear facilities, San Onofre and Diablo Canyon, were built to withstand an earthquake of only 7.5.

An 8.9 earthquake is many times more powerful.

Southern California’s Orange County Register reported Saturday that the owner of San Onofre said the plant in fact was built to withstand only a 7.0 earthquake.

Scientists are predicting a major earthquake is likely in California sometime in the next 10 years.

California's San Onofre and Diablo Canyon nuclear plants are also sitting on the edge of the Pacific Ocean, convenient to any tsunamis that might be speeding their way at up to 500 mph, and in seismically active areas..

The owners of both facilities, however, would like to have the operating licenses of their aging nukes extended for an additional 20 years past the current 40 year licenses.

Diablo Canyon applied for such a license extension in November 2009, and could have it granted by the Nuclear Regulatory Commission as soon as next year.

But the Japan disaster demonstrates not only why this should not happen, but also why Diablo Canyon and San Onofre should cease operations immediately.